초록 ▼

A mold assembly for making a polymeric container that is shaped to exhibit superior characteristics of light weighting, stability against toppling and resistance to stress cracking includes a conventional cylindrical body portion having a longitudinal axis and a circumferential sidewall and a novel

A mold assembly for making a polymeric container that is shaped to exhibit superior characteristics of light weighting, stability against toppling and resistance to stress cracking includes a conventional cylindrical body portion having a longitudinal axis and a circumferential sidewall and a novel bottom portion. The bottom portion includes a central pushup area of uniformity that is substantially uniform within a spatial rotation about the longitudinal axis. The area of uniformity has a radius R.sub.G. The bottom also includes a plurality of support feet that surround and protrude downwardly from the pushup area. Each of the support feet have a bottom support surface with an inner point of contact and an outer point of contact. The outer points of contact together define an outer contact radius R.sub.OC. The bottom portion as a whole has a radius of maximum width R.sub.BASE. A plurality of ribs are positioned in valleys between the support feet. Each of these ribs is positioned between and helps define two of the support feet. At least one of the ribs has a localized radius of curvature R.sub.C that intersects an arc connecting inner points of contact of two adjacent support feet. Advantageously, the radius of uniformity is within the range of about 16% to about 26% of R.sub.OC ; and R.sub.C is within the range of about 70% to about 10% of R.sub.BASE.

대표청구항 ▼

[ What is claimed is:] [1.]1. A mold assembly for making a polymeric container that is shaped to exhibit superior characteristics of light weighting, stability against toppling and resistance to stress cracking, comprising:a first mold surface defining a substantially cylindrical body portion having

[ What is claimed is:] [1.]1. A mold assembly for making a polymeric container that is shaped to exhibit superior characteristics of light weighting, stability against toppling and resistance to stress cracking, comprising:a first mold surface defining a substantially cylindrical body portion having a longitudinal axis and a circumferential sidewall; anda second mold surface defining a bottom portion comprising:a central pushup area of uniformity that is substantially uniform within a spatial rotation about the longitudinal axis, said area of uniformity having a radius R.sub.G ;a plurality of support feet surrounding and protruding downwardly from the pushup area, each of the support feet having a bottom support surface with an inner point of contact and an outer point of contact, said outer points of contacting together defining an outer contact radius R.sub.OC ; said bottom portion further having a radius of maximum width R.sub.BASE ;a plurality of ribs positioned in said valleys between said support feet, each of the ribs being positioned between and helping to define two of the support feet, at least one of said ribs having a localized radius of curvature R.sub.C that intersects an arc connecting inner points of contact of two adjacent support feet; and whereinsaid radius of uniformity is within the range of about 16% to about 26% of R.sub.OC ; and R.sub.C is within the range of about 70% to about 110% of R.sub.BASE.